Speedo gear

[BayouGold]

So i tried to install my new speedo gear i bought to compensate for the lower gears & everything went fine up until the point i tried to reinstall the gear assy into the xfer case. for some reason it won't seat all the way in & the o-ring starts bunching up. i turned it, spun the gear, pulled it completely off & put it back on & finally got fed up & put the old one back in. went & looked on stu olson's site & of course in his write up everything went like it was supposed to. that is to say he didn't mention any problems when he did his. i checked to make sure i had the right one & i do. anybody got any thoughts? 

[PaulW]

lift the rear tires off the ground, with the truck in neutral spin the rear drive shaft at the same time your pushing the speedo gear in.  they have to mesh while being pushed in.  don't forget to lube the o-ring.  it doesn't go in easy if the rubber is dry 

[BayouGold]

lift the rear tires off the ground, with the truck in neutral spin the rear drive shaft at the same time your pushing the speedo gear in.  they have to mesh while being pushed in.  don't forget to lube the o-ring.  it doesn't go in easy if the rubber is dry 

thank you oh wise one

[kirksjeep]

Lube the O-ring.  It is a tight fit to prevent leaking.  If the old on fit back in, and the new one doesn't I would have to guess it has to with the size of the new one.  Does the new gear slide into the cable housing as far as the old one?  If the plastic gears on the new speedo gear and the plastic gear on the rear transfercase shaft are meshing it will not allow the gear to slide all the way down.  If this is the case, push the speedo gear onto the cable mount and push the cable mount into the SYE tail housing as far as it will go.  Put the bolt in that holds the speedo gear in and apply a little pressure to the gear with the bolt.  Put you Jeep in nuetral and roll it a few feet.  Hopefully the gears will slip into place and then you can tighten the bolt all the way.  Good Luck.

[calvynandhobbs]

Geoff, we did something wrong when we install my speedo back into my tcase after installing the SYE. The speedo worked for a few miles and then just dropped off to zero and hasn't moved since. I opened it back up the other night and the gears are completely chewed away. It is destroyed, but I wanted a new speedo anyway since mine is way off with the 33s on my XJ and still running stock gears. Now I have a reason to buy a new one, but I have to figure out what we did wrong on the original install. The guys on NAXJA think the o-ring may have stuck and the gear seated crooked, but I don't know. What I do know is that my speedo doesn't work at all right now.

[BayouGold]

it's like kirk mentioned, the new one is so much bigger than the other one. it doesn't go all the way in. i tried putting the bracket over & tightening the bolt but all that did was bunch the o-ring even more. i didn't think about putting the rig in neutral & rolling it a little.roger i know mine has 4 different positions it can set in. is yours like that & if so did you have it set at the right pos?

[calvynandhobbs]

I think mine only has 2 positions it can set it, but I was reinstalling the original speedo gear in mine. My guess is that the o-ring bunched up and put it in crooked. Before I try installing another one I'll do a lot of reading on various methods to ensure everything is lined up correctly.

[calvynandhobbs]

The good thing about having an old XJ with the mechanical speedo is that they are cheap. I just ordered one from ChryslerPartsDirect for a whopping $6.51 plus shipping in the correct number of teeth for 3.55 gears and 33" tires. The 87-90 XJs only have one length speedo gear and it is different than all the other years. It is also mechanical verses electrical like the newer models.I got a lot of good information with part numbers and everything from here for my XJ.

http://www.go.jeep-xj.info/HowtoSpeedoGears.htm

[kirksjeep]

The good thing about having an old XJ with the mechanical speedo is that they are cheap. I just ordered one from ChryslerPartsDirect for a whopping $6.51 plus shipping in the correct number of teeth for 3.55 gears and 33" tires. The 87-90 XJs only have one length speedo gear and it is different than all the other years. It is also mechanical verses electrical like the newer models.I got a lot of good information with part numbers and everything from here for my XJ.

http://www.go.jeep-xj.info/HowtoSpeedoGears.htm

I know when I pulled it out, I mentioned how much longer the speedo gear was then others I had seen.   .  I guess that is the difference with the 87-90 XJ's, besides the 4wd vacuum switch on the back of the NP231 vs on top.